The major aim of the proposed research is to investigate age-dependent and time-dependent trajectories of English language acquisition among non-English language immigrants in the United States. After several decades of high levels of immigration, the United States has become the site of a complex, natural experiment in English acquisition among immigrants. In 2000, 25 million of the 31 million immigrants in the United States spoke a non-English and almost 16 million were not fully fluent in English. Minority language speakers who lack well-developed skills in English encounter numerous communicative obstacles in all of the major American social institutions including the educational system, the labor force, and the healthcare system, and as a result, face diminished prospects and negative life outcomes. [unreadable] [unreadable] Previous social science research investigating the acquisition of English among immigrants has relied on simple exposure and human capital models. This project extends previous research by incorporating theoretical frameworks from linguistics, psychology and sociology to investigate how processes of English acquisition unfold over time and within immigrants' life cycles. The first specific aim is to investigate the age-dependent and time-dependent parameters governing trajectories of English acquisition among immigrants. The second specific aim focuses on how immigrants' participation in key social institutions, such as the American educational system and the labor force, shapes processes of English acquisition. The third specific aim considers how trajectories of English acquisition are affected by the social contexts in which minority language speakers live. The primary statistical analyses are based on data from the 2000 U.S. Census. [unreadable] [unreadable] [unreadable]